Inverse drawing presses

ABSTRACT

An inverse drawing press has a movable cross-member and a fixed cross-member which carries the die. The movable cross-member carries a bottom for a container moved over the die and receiving the ingot. A punch carried by the bottom for the container separates the end of the bar in the die from the shoe and shear cuts off the shoe. A ram removes any residual metal from the container.

United States Patent 1 Doudet INVERSE DRAWING PRESSES [75] Inventor:Michel Doudet, Chatillon S/Bagneux,

France [731 Assigneez SECIM, Courbevoie, France [22] Filed: July 12,1971 [21] Appl. No.: 161,721

[52] US. Cl. 72/255, 72/263 [51] Int. Cl. B2lc 23/00 [58] Field ofSearch 72/257, 263, 255,

[56] References Cited UNITED STATES PATENTS 1,609,988 12/1926 Bull..72/255 June 12, 1973 3,530,702 9/1970 DeRidder 72/272 PrimaryExaminer-Charles W. Lanham Assistant Examiner-Robert M. RogersAttorney-CameromKerkam & Sutton [57] ABSTRACT An inverse drawing presshas a movable cross-member and a fixed cross-member which carries thedie. The movable crossmember carries a bottom for a container moved overthe die and receiving the ingot. A punch carried by the bottom for thecontainer separates the end of the bar in the die from the shoe andshear cuts off the shoe. A ram removes any residual metal from thecontainer,

2 Claims, 8 Drawing Figures PAIENIEBJUNI 21m I smzu a 1 INVERSE DRAWINGPRESSES BACKGROUND OF THE INVENTION container and further include a rammounted on the I fixed cross-member in the drawing axis to penetrateinto the interior of the container during displacement of the movablecross-member and of the container toward the fixed cross-member.

The bottom for the container, interposed between the container and themobile cross-member, may require replacement and it has already beenproposed to mount it on a support movable perpendicularly to the drawingaxis in such a way as to place on this support a base or bottom toreplace the used base bottom for the container by a simple sliding ofor. rotation of the movable support. At the end of the drawingoperation, there remains in the chamber of the container a residue ofthe ingot shaped like a cup extending along the walls of the chamber ina thin envelope due to the clearance between the die placed at the endof the ram and the wall of the chamber.

To remove this residue and envelope, it is generally pushed out by a ramfrom the container after withdrawal of the bottom of the container. Thebase of the cup is then sheared off and the envelope then forced fromthe interior usually with the die adhering to it. A new head is thenplaced on the extremity of the ram equal to the section of the containerand the new head is advanced in the container in such a way as to engagethe envelope and remove it.

During these steps, a new ingot is brought into the drawing axis betweenthe bottom of the container and the container which new ingot is thenmoved into the chamber of the container during its movement. Under thesecircumstances, it is necessary that there be between the extremewithdrawn position of the bottom of the container and the end of the rama distance equal at least to the length of an ingot plus the length ofthe container.

SUMMARY OF THE INVENTION The present invention has for its objectimprovements simplifying the charging operation of the new ingot and todecrease the length of the displacement of the movable cross-member thusproviding more compact presses.

In accordance with the present invention, the support for the bottom ofthe container is mounted on a carriage which can be moved into thedrawing axis by displacement of the base, the press including means forintroducingan ingot into said carriage when the bottom for the containeris placed in the drawing axis and includes means for moving said ingotinto the chamber of the container when the support is moved into thedrawing axis.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be describedwith reference to the accompanying drawings in which like referencecharacters indicate like parts. In these drawings, in which preferredembodiments of the present concept are shown,

FIGS. 1, 2, 3, 4, 5 and 6 show different phases of the cycle of a pressprovided with the improvements of thisinvention; and

FIGS. 7 and 8 show schematically a further improvement, FIG. 7 showingthe movable cross-member in its position at the end of the drawing cycleand FIG. 8

showing the movable cross-member in withdrawn posi- DESCRIPTION OF THEPREFERRED EMBODIMENTS With reference now to the several figures of thedrawings, the press has a fixed cross-piece 1 connected to a base bymountings not shown and a movable crosspiece 2 connected to the base bya plurality of pistons 3 for moving the cross-member 2 toward and awayfrom cross-member 1. The main drawing piston, not shown, drives movablecross-member 2 toward crossmember 1. A container 4 is connected to thebase by a plurality of pistons 5 and is provided with a pocket 41 toreceive the ingot.

Pocket 41 is closed on the side of the movable crossmember 2 by acontainer base 6 mounted on carriage 7 moved by piston 8 perpendicularto the drawing axis. A ram 9 is mounted on the fixed cross-member and isprovided at its extremity with a die or drawing nozzle 10 having across-section slightly less than that of chamber 41.

At the end of carriage 7 is pocket 11 in the axis of a pusher and chute12 for introduction of a new ingot 13.

FIG. 1 shows the position of the press at the end of the drawingoperation. The ingot, compressed between the ram and the bottom 6 ofcontainer 4 has extruded as a bar 131 moving through an axial opening inram 9. There remains in the bottom of chamber 41 a shoe 132 forming acup with a thin envelope 133 in the clearance between the die 10 andchamber 41 and adhering to the wall of chamber 41.

At the end of the drawing operation, an ingot 13 is brought to thecharging chute 12. with a piston 14 in the axis of the of pocket 11.

After the end of a drawing operation, movable crossmember 2 is withdrawnas shown in FIG. 2. At the same time, piston 14 pushes ingot 13 intoplace in pocket 11. At the same time, container 4 is moved toward thefixed cross-member 1 in such a way as to move shoe 132 out of chamber41. Shoe 132 is then cut off by shear 15 moving over the rear face ofcontainer 4. Bar 131, separated from the shoe, can then be removed fromthe press.

Container 4 is then moved to the position shown in FIG. 3, the die 10remaining within chamber 41. As seen in FIG. 3, ram 9 is mounted on asupport 16 sliding along fixed cross-member 1 and having a second ram 91carrying at its extremity a head 92 of diameter equal to that of chamber41 of container 4. Another die 101 may then be placed on the extremityof ram 9.

Container 4 is then moved again toward the fixed cross-member l as shownin FIG. 4. Head 92 moves charging chute 12 and into chamber 41 andscrapes the wall of this chamber thus removing envelope 132 and dietherefrom. At the same time, carriage 7 is moved perpendicularly to thedrawing axis by piston 18 in such a way that ingot 13, carried in pocket11, is moved into the drawing axis. The bottom 6 of container 4 isdisengaged at this time And then replaced if necessary. A chargingpiston 17 is mounted on movable cross-member 2 in the drawing axis.

After clearing of chamber 41, container 4 is moved off of ram 91 andinto position adjacent ram 9. Piston 17 then pushes ingot 13 intochamber 41 (FIG. 5). Ram 9, carrying on its extremity new die 101 ismeanwhile moved into the drawing axis by sliding support 16 along fixedcross-member 1. Carriage 7 is then moved to bring bottom 6 of container4 into position opposite the end of chamber 41 as seen in FIG. 6. Ondisplacing the movable cross-member 2 toward the fixed crossmember 1 bymeans of the main drawing piston, the bottom 6 of container 4 is placedagainst container 4 and closes it. The die 101 then moves into chamber41 and a new bar is formed by extrusion of ingot l3. During this stage,a new ingot can be mounted in charging chute 12.

In the embodiment of the present concept just described, shearing ofshoe 132 is carried out by a shear moved over the rear face of container4.

However, the drawing die 10 on the end of ram 9 generally has anenlarged entry to facilitate passage of the metal of the ingot intodrawing die 10. It follows that, after cutting off of shoe 132 by aknife 15, the end of bar 131 in the die has a slightly greater diameterthan that of the drawing die and therefore passes with difficultythrough it. Further, shearing may also cause burrs which resist removalof the bar. It is therefore necessary to exert on the bar a certainamount of force to remove it from the die. This is not inconvenient whenthe bars have a small diameter since the bars usually extend overapparatus located behind the press which apparatus provides thenecessary force to disengage the bar. However, when the bars have arelatively large diame ter, for example greater than 40 mm., the barextends, on leaving the press, onto a roller table which can provide nopulling force on the bar. Consequently, to disengage the bar from thedie, it is necessary, by reason of the locking of its end, either toexert a pulling force on the bar by hand or by a special pulling device.The invention has for a further object two improvements to overcomethese inconveniences.

Presses for manufacture of tubes already have used apparatus forseparation of the bar from the shoe in the form of a striker located inthe bottom of the container and in the drawing axis and including apunch of slightly less diameter than that of the drawing die andentering the drawing die by axial movement through the shoe thusseparating the bar from the shoe.

Usually, this punch is mounted on a base forming a piston slidablymounted in an axial chamber formed in the bottom of the container, theassembly thus including a piston actuated by an oil under pressure andacting on the punch with a force necessary to pass the punch through theshoe and enter the die.

This arrangement provides excellent separation of the bar avoiding burrsand any enlargement of the end of the bar but it is inconvenient inrequiring the addition, in the bottom of the container or in itscarriage,

of a supplementary piston and means for feeding this piston with oilunder pressure.

The improvements above-described in addition to the advantages whichthey provide for charging the ingot also facilitate separation of thebar from the shoe.

In another embodiment, the bottom of the container is provided with anaxial punch, per se known, and capable of detaching the bar from theshoe by axial displacement of the axial punch at the end of the drawingcycle by means 17 for moving the ingot into container FIGS. 7 and 8 showschematically and partially a press provided with these furtherimprovements.

FIG. 7 shows the position of the press at the end of the drawing cycle.The ingot, compressed between die 10 mounted on ram 9 and the bottom 6of container 4 passes through the die and forms bar 131, a shoe 132remaining between die 10 and bottom 6.

In this embodiment, the bottom of the container is provided with a rod18 forming a punch 181 of a diameter slightly less than that of the dieand mounted on a base 182 sliding in an axial opening 61 in the bottom 6of container 4.

This arrangement is per se known, passage 61 generally forming a chamberfor piston 182 formed by the base of the punch and driven when thechamber is fed with oil under pressure.

In accordance with the present invention, rod 18 is extended on the sideopposite the punch by a rod 183 which passes through carriage 7 forbottom 6 of container 4 and opens on the side opposite bottom 6.

Rod 183 being located in the axis of bottom 6 of container 4, that is inthe drawing axis, when the press is in drawing position, rod 183 is thuslocated opposite the extremity of piston rod 17.

In the first embodiment described above, piston 17 is used only tointroduce ingot 13 into container 4 after movement of carriage 7 placesingot 13 in pocket 11, and then in the drawing axis.

In the second embodiment of the present invention, piston 17 alsoactuates rod 18 by engaging the extremity of rod 183. Punch 181 thenenters the die as seen in FIG. 7 and separates bar 131 from shoe 132.

After this operation, movable cross-member 2 is withdrawn to theposition shown in FIG. 8, piston 12 being withdrawn, and rod 18 iswithdrawn. Shoe 132 can be removed, as previously indicated, by a shear15 displaced over the rear portion of container 4 or any other suitablemeans. Separation of bar 131 already having taken place, removal of theshoe is facilitated and the formation of burrs on the rod is avoided.Further, the end of bar 131 is perfectly disengaged since the punch 181has a diameter practically equal to that of the bar and enters the diethrough the enlarged portion thereof. Bar 131 can thus be removedwithout difficulty even if it has a large diameter since its extremityis completely disengaged from the die.

The rest of the cycle is carried out as indicated above. Ingot 13 isbrought into the drawing axis by displacement of carriage 7 alongmovable cross-member 2 and is then introduced by means of piston 17 intothe opening of container 4 after container 4 has been cleared by meansof second ram 91 provided with clearing die 92.

Piston 17 is withdrawn, the bottom 6 of container 4 is brought into thedrawing axis by displacement of carriage 7 and rod 18 returns by freemovement to withdrawn and initial position when bottom 6 of container4.is applied against container 4 and the ingot by the movement ofmovable cross-member 2 beginning a new drawing operation.

It is thus seen that the embodiment which has just been describedprovides separation of the bar from the shoe and a perfect disengagementof the extremity of the bar from the die.

It should be understood that, if the rod 18 remains in extended positionafter withdrawal of movable crossmember 2, it will be necessary towithdraw movable cross-member 2 sufficiently for bottom 6 of container 4to move behind the container when the container has been disengaged fromram 9. The additional distance then necessary corresponds to the depthof penetration of the punch in the drawing die. This being a minimum, nomarked inconvenience is introduced. On the other hand, if it is desiredto reduce the dimensions of the press as much as possible, a spring maybe placed in chamber 61 to withdraw rod 18 after return of piston 17.

The present invention is not limited to the details of the preferredembodiments discussed above. Modifications of these embodiments may bemade within the present inventive concept. The sliding support for thebottom 6 of container 4 and of the ram could, for example, be unitaryand move at the same time. Further, the moving supports could rotateabout an axis parallel to the drawing axis. Such a support for thebottom of the container could, for example, include two arms carryin gat their extremities a bottom for the container between which would beplaced two other arms connected at their extremities to a pocket for thenew ingot. Further, a replacement bottom for the container could beplaced in advance on the rotating support and thus avoid alternatingmovements of the support. Still further, piston 14 for introducing ingot13 into pocket 11 could be replaced by a push lever for the ingotactuated by the withdrawal movement of the movable cross-member 2.

What is claimed is:

1. An inverse drawing press for drawing a bar from an ingot comprising afixed cross-member, a movable cross-member means for moving saidcross-members toward and away from each other, a container having anaxial chamber for the ingot open adjacent said fixed cross-member andclosed when adjacent said movable cross-member, a bottom for saidcontainer, a carriage for said bottom on said movable cross-member anddisplaceabe in a plane perpendicular to the drawing axis, a pocket insaid carriage, an extension mounted on said fixed cross-member in thedrawing axis, a drawing die on said extension, said pocket being movableinto the drawing axis by displacement of said carriage, means forintroducing an ingot into said pocket when said bottom of said chamberis located in the drawing axis, means for moving the ingot into saidcontainer when said pocket in said carriage is in the drawing axis, apunch mounted for axial movement in said bottom of said container todetach the bar from the shoe, said punch being actuated at the end ofthe drawing cycle by said means for moving the ingot into saidcontainer.

2. A press as described in claim 1, said punch having a diameter ofslightly less than that of said die, a piston base for said punchsliding in a chamber in the axis of said bottom of said container, saidmeans for moving said ingot into said container including a shaft forsaid piston in the drawing axis, said shaft extending opposite saidpunch and passing through said carriage, said means for moving the ingotinto said container engaging the extremity of said shaft and actuatingsaid punch at the end of the drawing cycle.

1. An inverse drawing press for drawing a bar from an ingot comprising afixed cross-member, a movable cross-member means for moving saidcross-members toward and away from each other, a container having anaxial chamber for the ingot open adjacEnt said fixed cross-member andclosed when adjacent said movable cross-member, a bottom for saidcontainer, a carriage for said bottom on said movable cross-member anddisplaceab e in a plane perpendicular to the drawing axis, a pocket insaid carriage, an extension mounted on said fixed cross-member in thedrawing axis, a drawing die on said extension, said pocket being movableinto the drawing axis by displacement of said carriage, means forintroducing an ingot into said pocket when said bottom of said chamberis located in the drawing axis, means for moving the ingot into saidcontainer when said pocket in said carriage is in the drawing axis, apunch mounted for axial movement in said bottom of said container todetach the bar from the shoe, said punch being actuated at the end ofthe drawing cycle by said means for moving the ingot into saidcontainer.
 2. A press as described in claim 1, said punch having adiameter of slightly less than that of said die, a piston base for saidpunch sliding in a chamber in the axis of said bottom of said container,said means for moving said ingot into said container including a shaftfor said piston in the drawing axis, said shaft extending opposite saidpunch and passing through said carriage, said means for moving the ingotinto said container engaging the extremity of said shaft and actuatingsaid punch at the end of the drawing cycle.